Illumination devices, as daily consuming products, have undergone great change with the development of the economic society and the emergence of new light sources such as fluorescent lamp, energy saving lamp, LED lamp, and so on. The variety and the multiple choices of the light sources also make the illumination lamp industry advance to a new level. It is necessary to decorate the places such as city plazas, traffic roads, newly built communities, house decoration, super markets, office buildings, and so on by use of the illumination products, and therefore, new requirements occur for the illumination products.